> Your Intel mac was stuck in the past while everyone paying attention on PCs were already enjoying TSMC 7nm silicon in the form of AMD Zen processors.

This is basically it. Coming from dated Intel CPUs, Mac users got a shockingly good upgrade when the M-series computers were released. That amplified Apple's claims of Macs being the fastest computers, even when some key metrics (such as disk performance) were significantly behind PC parts in reality.

Yes, they're still better in performance/watt - but the node difference largely explains it like you were saying.